ABSTRACT
The cuticle of social insects is a barrier against desiccation and a channel for chemical communication, two characteristics fundamental to the success of this group. The compounds present in the cuticle interact dynamically in order to achieve a balance between these two functions. Thus, viscosity correlates with waterproofing, whereas fluidity correlates with effective communication. Temperature variation can cause the cuticular hydrocarbon (CHC) layer of the cuticle to change in order to maintain body homeostasis. Thus, in this study, we tested the hypothesis that wasps with different body sizes and nest types will differ in their tolerance to temperature variation and ability to respond by changing cuticular chemical composition. To test this hypothesis, workers of three species of social wasps with different body sizes and nests, both with or without envelope, were subjected to different temperatures under controlled conditions. Cuticular compounds were analyzed by gas chromatography coupled to mass spectrometry (GC/MS). Results show that tolerance to temperature variation is not directly related to either wasp size or nesting type. An increase in the percentage of linear alkanes and a decrease in the percentage of branched alkanes were correlated with increased temperature. Thus, instead of either body size or nest type, tolerance to temperature variation seems to be mediated by the changing chemical composition of the cuticle.
Subject(s)
Animal Shells/chemistry , Thermotolerance , Wasps/physiology , Alkanes/analysis , Animal Shells/metabolism , Animals , Wasps/metabolismABSTRACT
Abstract The social wasps have a remarkable system of organization in which chemical communication mediate different behavioral interactions. Among the compounds involved in this process, cuticular hydrocarbons are considered the main signals for nestmate recognition, caste differentiation, and fertility communication. The aims of this study were to describe the cuticular chemical compounds of the species Mischocyttarus consimilis, Mischocyttarus bertonii, and Mischocyttarus latior, and to test whether these chemical compounds could be used to evaluate differences and similarities between Mischocyttarus species, using gas chromatography coupled to mass spectrometry (GC-MS). Workers from these three species presented a variety of hydrocarbons ranging from C17 to C37, and among the compounds identified, the most representative were branched alkanes, linear alkanes and alkenes. The results revealed quantitative and qualitative differences among the hydrocarbon profiles, as confirmed by discriminant analysis. This study supports the hypothesis that cuticular chemical profiles can be used as parameters to identify interspecific and intercolony differences in Mischocyttarus, highlighting the importance of these compounds for differentiation of species and populations.
ABSTRACT
Social wasps can face many challenges during their colony cycle, including the presence of parasites. The order Strepsiptera is among the main parasites of the wasp genus Polistes. The aim of this study was to evaluate the effect of an endoparasite species on the host Polistes ferreri, with the hypothesis that females of this social wasp would undergo morphophysiological alterations as well as changes in their cuticular chemical profile caused by the obligate endoparasite. On average, parasitism was found in 10% of the colonies studied. All the parasitized females showed filamentous ovarioles without developing oocytes, which indicates a physiological castration. Moreover, the endoparasites present in the gaster of females caused its volume to increase, and the presence of endoparasites changed the cuticular chemical profiles of females, confirming our hypothesis. It is likely that this parasitism effect could hamper the maintenance of wasp colonies.
